Heat treatment of rapidly solidified Fe−Cr−Zr−B alloys

The crystallization behaviour of amorphous melt spun Fe_82?x?yCr₁₈Zr_xB_y (x=0–8, y=10–20) ribbons have been investigated using differential scanning calorimetry. The crystallization temperature and crystallization behaviour change with varzing Zr and B content. The microstructural development during annealing of amorphous Fe₆₄Cr₁₈Zr₈B₁₀ has been investigated by a combination of transmission electron microscopy and energy dispersive X-ray microanalysis. Isothermal annealing for 2 h at temperatures in the range 600–1000°C produces a variety of different microstructures depending on the annealing temperature. At 600°C, the amorphous alloy partially crystallizes to a form a microstructure consisting of 9 nm sized bee ferrite grains embedded in an amorphous matrix. At temperatures in the range 700–900°C, the alloy microstructure transforms into a mixture of bee ferrite, faulted fcc MB₁₂ boride particles and tetragonal M₃B boride particles. At 1000°C, the faulted fcc MB₁₂ boride particles are replaced by orthorhombic M₄B boride particles.     

Annealing of thin B/Nb<Subscript>2</Subscript>N bilayers,B/Nb bilayers and Nb/B/Nb trilayers via rapid thermal processing (RTP)

B/Nb and B/Nb₂N bilayers and Nb/B/Nb trilayers of about 550 nm total thickness have been deposited on Si(100) wafers with 100 nm thermally grown oxide. Nb and B layers were deposited by magnetron sputtering. Nb₂N layers were prepared by nitridation of Nb films via rapid thermal processing (RTP). The samples were annealed subsequently at temperatures between 600 and 1,200 °C in an RTP system under Ar or NH₃ gas flow to study interdiffusion and reactivity of niobium, boron and nitrogen. Formation of phases was investigated by X-ray diffraction (XRD); surface morphology and roughness were studied via scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. Elemental depth profiles of selected samples were recorded by secondary ion mass spectrometry (SIMS). Annealing of the B/Nb bilayers and Nb/B/Nb trilayers under Ar leads to the formation of Nb₃B₂ at 1,200 °C at the B/Nb interface. At lower temperatures the high oxygen content in the boron layer is supposed to hinder the formation of borides due to formation of glass-like boron oxides. In NH₃ several niobium nitrides are formed but no boride phases. Here again the reactivity of boron with niobium is suppressed by the high oxygen content and boron oxide formation. During annealing of the B/Nb₂N bilayers no borides were formed indicating that well-formed Nb₂N is an effective diffusion barrier for B.     

Die Perthioborate RbBS3, TIBS3 und TI3B3S10

The Perthioborates RbBS₃, TIBS₃, and Tl₃B₃S₁₀ . RbBS₃ (P2₁/c, a=7.082(2) Å, b=11.863(4) Å, c=5.794(2) Å, β=106.54(2)°) was prepared as colourless, plate-shaped crystals by reaction of stoichiometric amounts of rubidium sulfide, boron, and sulfur at 600°C and subsequent annealing. TlBS₃ (P2₁/c, a=6.874(3) Å, b=11.739(3) Å, c=5.775(2) Å, β=113.08(2)°) which is isotypic with RbBS₃ was synthesized from a sample of the composition Tl₂S · 2 B₂S₃. The glassy product which was obtained after 7 h at 850°C was annealed in a two zone furnace for 400 h at 400→350°C. Yellow crystals of TlBS₃ formed at the warmer side of the furnace. Tl₃B₃S₁₀ (P1 , a=6.828(2) Å, b=7.713(2) Å, c=13.769(5) Å, α=104.32(2)°, β=94.03(3)°, γ=94.69(2)°) was prepared as yellow plates from stoichiometric amounts of thallium sulfide, boron, and sulfur at 850°C and subsequent annealing. All compounds contain tetrahedrally coordinated boron. The crystal structures consist of polymeric anion chains. In the case of RbBS₃ and TlBS₃ nonplanar five-membered B₂S₃ rings are spirocyclically connected via the boron atoms. To obtain the anionic structure of Tl₃B₃S₁₀ every third B₂S₃ ring of the polymeric chains of MBS₃ is to be substituted by a six-membered B(S₂)₂B ring.     

Na6[B18Se17]: The First Selenoborato‐closo‐dodecaborate with a Polymeric Chain Anion

Systematic studies on selenoborates containing a B₁₂ cluster entity and alkali metal cations led to the new crystalline phase Na₆[B₁₈Se₁₇] which consists of a icosahedral B₁₂ cluster completely saturated with trigonal‐planar BSe₃ units and sodium counter‐ions. Neighbouring cluster entities are connected in one direction via exocyclic selenium atoms forming the infinite chain anion ([B₁₈Se₁₆Se_2/2]^6–)_∞. The new chalcogenoborate was prepared in a solid state reaction from sodium selenide, amorphous boron and selenium in evacuated carbon coated silica tubes at a temperature of 850 °C. Na₆[B₁₈Se₁₇] crystallizes in the monoclinic space group C2/c (no. 15) with a = 18.005(4) Å, b = 16.549(3) Å, c = 11.245(2) Å, β = 91.35(3)° and Z = 4.     

Na2B2S5 and Li2B2S5: Two Novel Perthioborates with Planar 1,2,4-Trithia-3,5-Diborolane Rings

For the first time perthioborates with trigonal planar coordination of boron were prepared. Na₂B₂S₅ (Pnma, a = 12.545(2) Å, b = 7.441(1) Å, c = 8.271(1) Å, Z = 4) and Li₂B₂S₅ (Cmcm, a = 15.864(1) Å, b = 6.433(1) Å, c = 6.862(1) Å, Z = 4) were obtained by reaction of the metal sulfides with stoichiometric amounts of boron and an excess of sulfur (effective molar ratio M:B:S = 1:1:4) at 600°C (650°C) and subsequent annealing. The non-isotypic structures contain exactly planar [B₂S₅]^2? groups consisting of five-membered B₂S₃ rings with one additional exocyclic sulfur on each of the boron atoms. The alkaline metal cations are four-coordinate (lithium) and (four + four)-coordinate (sodium) respectively.     

Li5B7S13 und Li9B19S33: Zwei Lithiumthioborate mit neuen hochpolymeren Anionengerüsten

Li₅B₇S₁₃ and Li₉B₁₉S₃₃: Two Lithium Thioborates with Novel Highly Polymeric Anion Networks Li₅B₇S₁₃ (C2/c; a = 17.304(2) Å, b = 21.922(3) Å, c = 12.233(2) Å, β = 134.91(1)°; Z = 8) and Li₉B₁₉S₃₃ (C2/c; a = 23.669(9) Å, b = 14.361(3) Å, c = 12.237(3) Å, β = 103.77(2)°; Z = 4) were prepared by reaction of stoichiometric amounts of lithium sulfide, boron, and sulfur at 750°C (Li₅B₇S₁₃) and 700°C (Li₉B₁₉S₃₃) with subsequent annealing. The crystal structures consist of interpenetrating, polymeric boron sulfur anion networks which are formed by corner-sharing of B₄S₁₀ and B₁₀S₂₀ units (Li₅B₇S₁₃), or B₁₉S₃₆ units (Li₉B₁₉S₃₃). The lithium cations are situated in between with a strong disorder in Li₉B₁₉S₃₃.     

Drei neue Selenoborato-closo-dodekaborate: Synthesen und Kristallstrukturen von Rb8[B12(BSe3)6], Rb4Hg2[B12(BSe3)6] und Cs4Hg2[B12(BSe3)6]

Three Novel Selenoborato- closo -dodecaborates: Syntheses and Crystal Structures of Rb₈[B₁₂(BSe₃)₆], Rb₄Hg₂[B₁₂(BSe₃)₆], and Cs₄Hg₂[B₁₂(BSe₃)₆] The three selenoborates Rb₈[B₁₂(BSe₃)₆] (P1, a = 10.512(5) Å, b = 10.450(3) Å, c = 10.946(4) Å, α = 104.53(3)°, β = 91.16(3)°, γ = 109.11(3)°, Z = 1), Cs₄Hg₂[B₁₂(BSe₃)₆] (P1, a = 9.860(2) Å, b = 10.740(2) Å, c = 11.078(2) Å, α = 99.94(3)°, β = 90.81(3)°, γ = 115.97(3)°, Z = 1), and Rb₄Hg₂[B₁₂(BSe₃)₆] (P1, a = 9.593(2) Å, b = 10.458(2) Å, c = 11.131(2) Å, α = 99.25(3)°, β = 91.16(3)°, γ = 116.30(3)°, Z = 1) were prepared from the metal selenides, amorphous boron and selenium by solid state reactions at 700 °C. These new chalcogenoborates contain B₁₂ icosahedra completely saturated with six trigonal-planar BSe₃ entities functioning as bidentate ligands to form a persubstituted closo-dodecaborate anion. The two isotypic compounds Rb₄Hg₂[B₁₂(BSe₃)₆] and Cs₄Hg₂[B₁₂(BSe₃)₆] are the first selenoborate structures containing a transition metal which are characterized by single crystal diffraction.     

Na2B2Se7, K2B2S7 und K2B2Se7: Drei Perchalkogenoborate mit neuem polymeren Anionengerüst

Na₂B₂Se₇, K₂B₂S₇, and K₂B₂Se₇: Three Perchalcogenoborates with a Novel Polymeric Anion Network Na₂B₂Se₇ (I 2/a; a = 11.863(4) Å, b = 6.703(2) Å, c = 13.811(6) Å, β = 109.41(2)°; Z = 4), K₂B₂S₇ (I 2/a; a = 11.660(2) Å, β = 6.827(1) Å, c = 12.992(3) Å, β = 106.78(3)°; Z = 4), and K₂B₂Se₇ (I 2/a; a = 12.092(4) Å, b = 7.054(2) Å, c = 13.991(5) Å, β = 107.79(3)°; Z = 4) were prepared by reaction of stoichiometric amounts of sodium selenide (potassium sulfide) with boron and sulfur or of potassium selenide and boron diselenide, respectively, at 600°C with subsequent annealing. The crystal structures consist of polymeric anion chains of composition ([B₂S₇]^2?)_n or ([B₂Se₇]^2?)_n formed by spirocyclically connected five-membered B₂S₃ (B₂Se₃) rings and six-membered B₂S₄ (B₂Se₄) rings. The nine-coordinate alkaline metal cations are situated in between.     

Phase formation and controlled nanostructuring in amorphous Fe80B20 alloy

The temperature dependence of the volume fraction of the crystalline phase in Fe₈₀B₂₀ amorphous alloy is calculated using equations from the homogeneous nucleation theory of binary systems. It is shown that the crystallization of Fe₈₀B₂₀ alloy is two-stage, as is confirmed by the experimental data obtained by means of highly sensitive dilatometry and X-ray diffractometry. On the basis of results of calculations performed within the theory of the high-temperature stability of amorphous alloys, two areas of its practical application are proposed: (i) enhancing the thermal stability of amorphous alloys by isothermal annealing in the range of temperatures where crystalline nuclei can transition to the amorphous phase; (ii) controlled nanostructuring of the amorphous state with different modes of treatment. Methods are proposed for obtaining the nanostructured state from the initial amorphous state. Alloys in the nanocrystalline state are obtained, as is confirmed by the results from electron microscope investigations.     

Metalloktaederdoppel in den Clusterverbindungen Gd10I16(C2)2 und Gd10Br15B2/Tb10Br15B2

Gd₁₀I₁₆(C₂)₂ and Gd₁₀Br₁₅B₂/Tb₁₀Br₁₅B₂ Cluster Compounds with M₁₀ Twin Octahedra The compound Gd₁₀I₁₆(C₂)₂ can be prepared from Gd metal, GdI₃ and C at 950 °C. It crystallizes in P1 with a = 10.463(4) Å, b = 16.945(6) Å, c = 11.220(4) Å, α = 99.15(3)°, β = 92.68(3)° und γ = 88.06(3)°. Gd₁₀Br₁₅B₂ is formed between 900 und 950 °C, Tb₁₀Br₁₅B₂ between 900 und 930 °C from stoichiometric amounts of the rare earth metals, tribromide and boron. Both compounds crystallize in the space group P1 for Gd₁₀Br₁₅B₂ with a = 8.984(2) Å, b = 9.816(2) Å, c = 10.552(5) Å, α = 91.14(3)°, β = 114.61(3)° and γ = 110.94(3)° and for Tb₁₀Br₁₅B₂ with a = 8.939(4) Å, b = 9.788(3) Å, c = 10.502(2) Å, α = 91.19(3)°, β = 114.51(3)° and γ = 111.10(2)°. In the crystal structures of all three compounds the rare earth metals form edge‐shared Ln₁₀ twin octahedra. In Gd₁₀I₁₆(C₂)₂ the Gd octahedra are centered with C₂ groups (d_C–C = 1.43(7) Å). In Ln₁₀Br₁₅B₂ (Ln = Gd, Tb) the octahedra contain single boron atoms. The clusters are connected through halide atoms to chains [Ln₁₀(Z)₂X X X ]. Adjacent chains are fused threedimensionally via I I for the Gd iodide carbide and via Br Br for the bromide borides of Gd und Tb. It is interesting to see an identical pattern of connection between the chains for the reduced oxomolybdates, e. g. PbMo₅O₈.     

Preparation and characterization of the Ti/IrO<Subscript>2</Subscript>/WO<Subscript>3</Subscript> as supercapacitor electrode materials

WO₃ films have been prepared onto IrO₂-coated Ti substrate by electro-deposition, and as-deposited and annealed films have been characterized by using Raman spectroscopy. It was found that the asdeposited film consists of orthorhombic WO₃ · H₂O phase, which transforms to amorphous WO₃ by annealing at 250°C and to monoclinic phase by annealing at and above 350°C. All electrochemical experiments were carried on Ti/IrO₂/WO₃ annealed at 450°C. The open-circuit potential could change significantly due to the hydration of the coating film. However this process is fairly slow. Reproducible voltammograms could be obtained quickly, further revealing high electrochemical stability of the Ti/IrO₂/WO₃ electrode. And the shapes of CV show the approximate rectangular mirror image, showing the typical characteristic of capacitive behavior. The specific capacitance obtained at a scan rate of 50 mV s⁻¹ is 46 F g⁻¹.     

Cs2B2S4 – Ein Salz der dimeren Metathioborsäure

Cs₂B₂S₄ – A Derivative of the Dimeric Metathioboric Acid Cs₂B₂S₄ (structure: I4₁/acd; a = 7.270(1) Å, c = 35.737(7) Å; Z = 8; substructure: I4/mmm; a′ = 5.141(1) Å, c′ = 17.868(4) Å, Z = 2) is prepared by the reaction of cesium sulfide with stoichiometric amounts of boron and sulfur (effective molar ratio M:B:S = 2:2:4) at 600°C and subsequent annealing. The crystal structure contains isolated [B₂S₄]^2? groups consisting of four-membered B₂S₂ rings with two exocyclic sulfur atoms on each of the boron atoms. The cesium cations are nine-coordinate between these rings. The structural feature of two edge-sharing BS₃ groups forming an isolated anion appears for the first time in thioborate chemistry, although it is known as a part of the polymeric network in B₂S₃.     

Crystallization of MgFe2O4 from a glass in the system K2O/B2O3/MgO/P2O5/Fe2O3

Spherical magnetic Mg-Fe-O nanoparticles were successfully prepared by the crystallization of glass in the system K₂O/B₂O₃/MgO/P₂O₅/Fe₂O₃. The magnetic glass ceramics were prepared by melting the raw materials using the conventional melt quenching technique followed by a thermal treatment at temperatures in the range 560–700 °C for a time ranging from 2 to 8 h. The studies of the X-ray diffraction, electron microscopy and FTIR spectra confirmed the precipitation of finely dispersed spherical (Mg, Fe) based spinel nanoparticles with a minor quantity of hematite (α-Fe₂O₃) in the glass matrix. The average size of the magnetic nano crystals increases slightly with temperature and time from 9 to 15 nm as determined by the line broadening from the XRD patterns. XRD studies show that annealing the glass samples for long periods of time at temperature ≥604 °C results in an increase of the precipitated hematite concentration, dissolution of the spinel phase and the formation of magnesium di-borate phase (Mg₂B₂O₅). For electron microscopy, the particles were extracted by two methods; (i) replica extraction technique and (ii) dissolution of the glass matrix by diluted acetic acid. An agglomeration of the nano crystals to larger particles (25–35 nm) was observed.     

Phosphaniminato-Komplexe von Bor. Synthese und Kristallstrukturen von [BBr2(NPMe3)]2, [B2Br3(NPiPr3)2]Br, [B2(NPEt3)4]Br2, [B2Br2(NPPh3)3]BBr4 und [{B2(NMe2)2}2(NPEt3)2]Cl2

Phosphoraneiminato Complexes of Boron. Syntheses and Crystal Structures of [BBr₂(NPMe₃)]₂, [B₂Br₃(NPⁱPr₃)₂]Br, [B₂(NPEt₃)₄]Br₂, [B₂Br₂(NPPh₃)₃]BBr₄ and [{B₂(NMe₂)₂}₂(NPEt₃)₂]Cl The bromoderivatives of the title compounds are prepared from the corresponding silylated phosphoraneimines Me₃SiNPR₃ and boron tribromide. The boron subcompound [{B₂(NMe₂)₂}₂(NPEt₃)₂]Cl₂ derives from Me₃SiNPEt₃ and B₂Cl₂(NMe₂)₂. All complexes are characterized by NMR and IR spectroscopy as well as by crystal structure determinations. [BBr₂(NPMe₃)]₂ (1): Space group P2₁/n, Z = 2, R = 0.031. Lattice dimensions at ?50°C: a = 723.8, b = 894.2, c = 1305.4 pm, β = 92.35°. 1 forms centrosymmetric molecules in which the boron atoms are linked via μ₂-N bridges of the NPMe₃^? groups of from B₂N₂ four-membered rings with B? N distances of 149.9 and 150.9 pm. B₂Br₃(NPⁱPr₃)₂]Br (2): Space group P2₁, Z = 2, R = 0.059. Lattice dimensions at ?80°C: a = 817.6, b = 2198.7, c = 851.5 pm, β = 115.09°. In the cations of 2 the boron atoms are lined via the μ₂-N atoms of the NPⁱPr₃^? groups to form planar, asymmetric B₂N₂ four-membered rings with B? N distances of 143 and 156 pm. [B₂(NPEt₃)₄[Br₂·4CH₂Cl₂ (3): Space group C2/c, Z = 4, R = 0.042. Lattice dimensions at ?50°C: a = 1946.1, b = 1180.3, c = 2311.3 pm, β = 101.02°. The structure contains centrosymmetric dications in which both the boron atoms are lined by the N atoms of two of the NPEt₃^? groups to form a B₂N₂ four-membered ring with B? N distances of 149.6 pm. The remaining two NPEt₃^? groups are terminally bonded with very short B? N distances of 133.5 pm. B₂Br₂(NPPh₃)₃]BBr₄ (4): Space group P1 , Z = 2, R = 0.065. Lattice dimension at ?50°C: a = 1025.7, b = 1496.1, c = 1807.0 pm, α = 85.09°, β = 82.90°, γ = 82.72°. In the cation the boron atoms are lined via the μ₂-N atoms of two of the NPPh₃^? groups to form a nearly planer B₂N₂ four-membered ring with B? N distances of 149.3-153.1 pm. The third NPPh₃³ group is terminally connected with teh sp² hybridized boron atom and with a B? N distance of 134.1 pm along with an almost linear BNP bond angle of 173.6°. [{B₂(NMe₂)₂}₂(NPEt₂)₂]Cl₂ · 3CH₂Cl₂ (5): Space group C2/c, Z = 4, R = 0.098. Lattice dimensions at ?70°C: a = 1557.9, b = 1294.7, c = 2122.9 pm, β = 96.08°. The structure of 4 contains centrosymmetric dications in which two by two B-B dumb-bells are linked via the μ₂-N atoms of the two NEPt₃^? groups to form B₄N₂ six-membered rings with B? N distances of 150 and 156 pm and B-B distances of 173 pm. The B? N distances of the terminally bonded NMe₂^? groups correspond to 138 pm double bonds.     

Structure of the monoclinic modification of Re3B

By powder X-ray diffraction the structure of the monoclinic modification of Re₃B is studied. The phase is obtained under high pressure and high temperature (10 GPa, 1800°C) using nanocrystalline rhenium and amorphous boron. The results of the comparative crystal chemical analysis are reported.     

Li6+2x[B10Se18]Sex (x ≈ 2), ein ionenleitendes Doppelsalz

Li_6+2x[B₁₀Se₁₈]Se_x (x ≈ 2), an Ion‐conducting Double Salt Li_6+2x[B₁₀Se₁₈]Se_x (x ≈ 2) was prepared in a solid state reaction from lithium selenide, amorphous boron and selenium in evacuated carbon coated silica tubes at a temperature of 800 °C. Subsequent cooling from 600 °C to 300 °C gave amber colored crystals with the following lattice parameters: space group I2/a (at 173 K); a = 17.411(1) Å, b = 21.900(1) Å, c = 17.820(1) Å, β = 101.6(1)°. The crystal structure contains a well‐defined polymeric selenoborate network of composition ([B₁₀Se₁₆Se_4/2]^6?)_n consisting of a system of edge‐sharing [B₁₀Se₁₆Se_4/2] adamantanoid macro‐tetrahedra forming large channels in which a strongly disorderd system of partial occupied Li⁺ cations and additional disordered Se^2? anions is observed. The crystal structure of the novel selenoborate is isotypic to Li_6+2x[B₁₀S₁₈]S_x (x ≈ 2) [1]. X‐ray and ⁷Li magic‐angle spinning NMR data suggest that the site occupancies of the three crystallographically distinct lithium ions exhibit a significant temperature dependence. The lithium ion mobility has been characterized by detailed temperature dependent NMR lineshape and spin‐lattice relaxation measurements.     

A co-precipitation and annealing route to the large-quantity synthesis of boron nitride nanotubes

A novel co-precipitation and annealing route to the large-quantity synthesis of boron nitride nanotubes (BNNTs), using amorphous boron powder, iron nitrate nonahydrate (Fe(NO₃)₃·9H₂O) and urea (CO(NH₂)₂) as the raw materials, was demonstrated. An intermediate Fe(OH)₃·B was firstly prepared through a co-precipitation process and then annealed in flowing ammonia atmosphere at 1200 °C. It was found that the heat treatment at 800 °C during the annealing process could favor the growth of BNNTs. The BNNTs had an average diameter of 70 nm and possessed bamboo and quasi-cylindrical structures. The annealing temperature greatly affected the formation of BNNTs. Only BN particles could be obtained at lower temperature (e.g. 1100 °C), whereas thorn-like nanosheet-decorated BNNTs were fabricated at higher temperature (e.g. 1300 °C). A combination mechanism of solid–liquid–solid (SLS) and vapor–liquid–solid (VLS) model was suggested to be responsible for the growth of BNNTs.     

Planar ZrO2 Waveguides Prepared by the Sol-Gel Process: Structural and Optical Properties

ZrO₂ waveguides are prepared by the sol-gel process from a solution containing zirconiumn-propoxide and acetylacetone in propanol-2. Structural characterizations are investigated for different annealing temperatures using suitable techniques including Waveguide Raman Spectroscopy, Electron Microscopy and Atomic Force Microscopy. Films are amorphous at 300°C and the pure ZrO₂ tetragonal crystalline phase appears beyond 400°C. Crystallized films present a dense, uniform and polycrystalline structure made up by randomly oriented nanocrystallites, the diameter of which increases from 38 Å at 400°C to 53 Å at 600°C. Waveguides are at least monomode TE₀ at 632.8 nm. At this wavelength, optical losses are about, 0.8±0.2dB/cm for amorphous layers and increase up to 2.5±0.4 dB/cm for 600°C heat-treated waveguides.     

B<Subscript>12</Subscript>-induced formation of stishovite in sol–gel produced amorphous SiO<Subscript>2</Subscript> matrices

Composites containing vitamin B₁₂ (cyanocobalamin) dispersed in amorphous silica xerogel were studied structurally as a function of annealing temperature. Silica xerogel samples were prepared by the sol–gel method using an ethanol:H₂O:TEOS molar ratio of 4:11.6:1 and loaded with cyanocobalamin. We found that the structure of the cobalamin is unaltered, although decoordination of the benzimidazole nucleobase of B₁₂, whereas the amorphous quartz structure of the matrix is maintained under heat-treatment without low-cristobalite phase transformation, typically of this kind of materials. We found in our samples partial crystallization of the glass matrix in form of stishovite obtained at very lower pressure than those specified by the phase diagram, and temperatures about 400 °C due to the presence of vitamin B₁₂. The presence of stishovite is corroborated by the Rietveld refinement method.     

Sr3(BS3)2 und Sr3(B3S6)2: Zwei neue nicht‐oxidische Chalkogenoborate mit trigonal‐planar koordiniertem Bor

Sr₃(BS₃)₂ and Sr₃(B₃S₆)₂: Two Novel Non‐oxidic Chalcogenoborates with Boron in a Trigonal‐Planar Coordination The thioborates Sr₃(BS₃)₂ and Sr₃(B₃S₆)₂ were prepared from strontium sulfide, amorphous boron and sulfur in solid state reactions at a temperature of 1123 K. In a systematic study on the structural cation influence on this type of ternary compounds, the crystal structures were determined by single crystal X‐ray diffraction. Sr₃(BS₃)₂ crystallizes in the monoclinic spacegroup C2/c (No. 15) with a = 10.187(4) Å, b = 6.610(2) Å, c = 15.411(7) Å, β = 102.24(3)° and Z = 4. The crystal structure of Sr₃(B₃S₆)₂ is trigonal, spacegroup R3¯ (Nr. 148), with a = 8.605(1) Å, c = 21.542(4) Å and Z = 3. Sr₃(BS₃)₂ contains isolated [BS₃]^3— anions with boron in a trigonal‐planar coordination. The strontium cations are found between the layers of orthothioborate anions. Sr₃(B₃S₆)₂ consists of cyclic [B₃S₆]^3— anions and strontium cations, respectively.